Hot Water Baseboard Gurgling, no bleeder...

amin1992

Hi guys, I really appreciate you all taking the time to read my post and help me out.

Just purchased my first home that has hot water baseboard radiators. I know they make some pinging and stuff here and there but was excited to have this radiant heat instead of blowing vents and ductwork.

Everytime the thermostat kicks the heat on, the first minute or so of the water flowing results in gurgling/bubbling noises from the baseboards. It is loud and wakes me up in the middle of the night. After a few minutes, the baseboards quiet down and all I hear is trickling noises like a babbling brook (not sure if that is normal either but I can deal with that noise).

Had a heating technician out who serviced our oil boiler. He said the zones needed purged of air so he ran water through the piping via a hose for a good long while. He said he got no air really out of the pipes, and the noise did not go away.

I asked him about some sort of purge valve being installed at the boiler and he said there was none and it would be difficult to install one because of "the way the pipes were installed".

I also searched for bleeder valves on the baseboard pipes and didn't see anything. Just a pipe coming up out of the floor and then running back down. Would there be a bleeder at every single baseboard? Or is there only one at the final baseboard in the zone? I have no clue which one is the last in the loop.

Thinking of calling a second technician out to maybe install some sort of bleeder/purge valve at the boiler - do you guys think that would fix it? How much does something like that typically cost? I'm holding off on it for now until I know it's a fix, as taking off work for boiler guys to come is getting hard.

Thank you alll so much.

pecmsg

Running city water and dumping it is a waste of time. He needs to use a pump and bucket to circulate air and remove it.

Can you post pic's of the piping around the boiler?

amin1992

Sorry I should have been more precise. I am in a rural location, with well water. I did not see exactly what he was doing but he did have some sort of pump hooked up to a hose and was draining multiple buckets

I can get some photos tonight. Thanks so much for responding.

Jamie Hall

One thing which can complicate purging... is if the baseboards are hooked up in series. It's all too easy for one or a few baseboards to sort of get left out of the procedure.

You need to run a lot of water through -- much higher flows than you would ever get normally -- to persuade the air to go away.

Intplm.

@ammin1992 You surely do need to purge that zone(s). I bet it sounds something like nuts and bolts being shaken in a can when the call for heat comes?

My guess is you do have a purge at each radiator or at the boiler designated for each zone.

Take a few pictures of the boiler and its associated piping. Post those pictures here for a better look.

I'm thinking that the boiler needs a purge set up at each zone near your boiler. You may want to consider having some type of microbubble air separator installed on your system too.
Get these things done and you will sleep well.

STEVEusaPA

Could just be piped wrong, not pumping away, picture please

amin1992

Intplm. said:

@ammin1992 You surely do need to purge that zone(s). I bet it sounds something like nuts and bolts being shaken in a can when the call for heat comes?

My guess is you do have a purge at each radiator or at the boiler designated for each zone.

Take a few pictures of the boiler and its associated piping. Post those pictures here for a better look.

I'm thinking that the boiler needs a purge set up at each zone near your boiler. You may want to consider having some type of microbubble air separator installed on your system too.
Get these things done and you will sleep well.

Hey there thanks for the response. Not really nuts and bolts. It's like a bubbling gurgle, almost like a cartoon ocean underwater noise is the best way I can think to describe it! Very loud.

I had a local small town boiler tech come to the house and he hooked up his hose to a valve that looked like a hose spigot with a round plug on it. But that is all we saw, he said no other air purger on it.

How much would it typically cost to add these? There are 2 zones. THanks for the help it means a lot

amin1992

STEVEusaPA said:

Could just be piped wrong, not pumping away, picture please

We get great heat in the home, all baseboards get nice and toasty. They just make a lot of noise is all!

Ironman

We really need pics to see how it's piped. You could have a monoflo system which can be extremely difficult to purge.

Also, you more than likely have something wrong in the system that allowed air to get in to begin with. The fact that you get heat from the BBs doesn't mean that the piping is correct. In fact, air in the system that can't b purged is a sure indication that it's not.

amin1992

Ironman said:

We really need pics to see how it's piped. You could have a monoflo system which can be extremely difficult to purge.

Also, you more than likely have something wrong in the system that allowed air to get in to begin with. The fact that you get heat from the BBs doesn't mean that the piping is correct. In fact, air in the system that can't b purged is a sure indication that it's not.

I'm sorry, I got side tracked and did not get photos last night. I will take a bunch tonight and post. Is there anything I can look for to see if it's a monoflo system? Maybe I can recall from memory.

T. J.

As a fellow homeowner (i.e., not a professional) with a hot-water heating system, I whole-heartedly recommend Dan Holohan's book on hydronic heating, Classic Hydronics, available on this site. It's not only an entertaining read, it's also a treasure trove of information on our systems. It helped me gain enough knowledge to get my system in shape and solve a lot of my air entrapment issues after moving into my old house.

Also, you've come to the right place. I've also received a lot of great information and advice from the professionals on this site including on my original post of my air entrapment issues (https://forum.heatinghelp.com/discussion/136177/constantly-purging-air-in-hydronic-system/p1).

Finally, believe it or not, pics help a lot. I mean, to me it just looked like a spaghetti of pipes at my boiler at first, but with one pic these guys identified a lot that was right and wrong with my system.

amin1992

T. J. said:

As a fellow homeowner (i.e., not a professional) with a hot-water heating system, I whole-heartedly recommend Dan Holohan's book on hydronic heating, Classic Hydronics, available on this site. It's not only an entertaining read, it's also a treasure trove of information on our systems. It helped me gain enough knowledge to get my system in shape and solve a lot of my air entrapment issues after moving into my old house.

Also, you've come to the right place. I've also received a lot of great information and advice from the professionals on this site including on my original post of my air entrapment issues (https://forum.heatinghelp.com/discussion/136177/constantly-purging-air-in-hydronic-system/p1).

Finally, believe it or not, pics help a lot. I mean, to me it just looked like a spaghetti of pipes at my boiler at first, but with one pic these guys identified a lot that was right and wrong with my system.

Thanks TJ, that is great to know. I plan on taking lots of pics tonight! I know my system isnt the most efficient (domestic coil, old cast iron boiler from the 70s) but I dont want to totally revamp the system now nor can I afford to. Just want to get rid of the air gurgling noise! Haha. Hopefully I can get some help here. Thanks

Intplm.

Looking forward to those pictures. Post them as soon as you can.

hot_rod

Also check the pressure in the system. Some times just boosting up the fill pressure a few pounds will get that problematic air out.

All closed loop systems should have an air separator right at the boiler. Air removal is best done at the hottest point in the system, at the boiler supply piping.

If you install a good air separator and the water is circulation through the system, within a few hours it should be 100% air free.

Piping and expansion tank connection needs to be correct, expansion tank near the inlet of the circulator pump.

So a handful of things need to be checked.

Fill pressure with an accurate gauge
Expansion tank to circulator relationship
Air separation device at or near the boiler

Ironman

amin1992 said:

Ironman said:

We really need pics to see how it's piped. You could have a monoflo system which can be extremely difficult to purge.

Also, you more than likely have something wrong in the system that allowed air to get in to begin with. The fact that you get heat from the BBs doesn't mean that the piping is correct. In fact, air in the system that can't b purged is a sure indication that it's not.

I'm sorry, I got side tracked and did not get photos last night. I will take a bunch tonight and post. Is there anything I can look for to see if it's a monoflo system? Maybe I can recall from memory.

A couple monoflo piping diagrams:




The monoflo Tees will have a red band or groove where the cone is.

This is not to be confused with a series loop where the main is looped directly through each rad.

amin1992

Thanks everyone for posting! I'm thinking I have a series system and not monoflo as I don't see tees. Here are photos of my boiler and also under the stairs at the only spot I can find under a baseboard heater that is in the foyer.

STEVEusaPA

Wow! And Yikes. Noises should be the least of your worries.

Ironman

Looks like the gauge is saying you only have 8 psi on the system. It should be minimum of 12 psi cold for a single story; 18 psi for a two story. That, combined with the circulator location, could be the source of your problem.

I cannot see the fill valve in your pics. It may be to left of the boiler, out of view. It may not be functioning properly. Without it maintaing sufficient pressure, and with the circulator pumping toward the Point Of No Pressure Change, instead of "pumping away", you could actually be flashing to steam in the higher points of the system.

You do have purge valves for each loop. The Tees that have boiler drains have a small chrome lever that turns 90* to shut the line while purging the respective loop.

Ironman

That primary control looks scary.

amin1992

Ironman said:

Looks like the gauge is saying you only have 8 psi on the system. It should be minimum of 12 psi cold for a single story; 18 psi for a two story. That, combined with the circulator location, could be the source of your problem.

I cannot see the fill valve in your pics. It may be to left of the boiler, out of view. It may not be functioning properly. Without it maintaing sufficient pressure, and with the circulator pumping toward the Point Of No Pressure Change, instead of "pumping away", you could actually be flashing to steam in the higher points of the system.

You do have purge valves for each loop. The Tees that have boiler drains have a small chrome lever that turns 90* to shut the line while purging the respective loop.

I had kept an eye on the pressure, I believe that first notch is 20 not 10 so it's hovering somewhere betweeen 15 and 20 PSI.

I think you are right and the fill valve is on the left. That is where domestic hot water enters and leaves the domestic coil too.

I think I just had the terminology wrong - yes those are the purge valves that the previous tech used to purge the system twice but it didn't fix the gurgling. I was thinking there should be some sort of automatic purge valve somewhere though right? That let's air out as it makes it's way to that point?

amin1992

Also Ironman, based on that first picture which is under the stairs directly under a baseboard, would you say I have series setup and not a monoflo?

Ironman

Yes to both questions. But let me clarify about the air separator: air separators (MBRs, air scoops) are not to be used when you have a compression tank like you have. They should only be used when you have an expansion tank with a bladder.

Here's why: your tank has to maintain an air cushion above the water in it to allow the water to expand when it's heated. Air will come out of solution where the water is at its lowest velocity and its hottest. In your case, that's the top of your boiler. The other places(s) are at high points in the system because air is lighter than water. If you'll notice, the compression tank is piped off of the top of your boiler so that air will go to the top of the tank maintaing the air cushion and eliminating it from the piping. This is the air removal system for your type of system. You CANNOT use an air separator with your system because it would soon cause your compression tank to become water logged with no room for expansion. Bladder expansion tanks MUST use an air separator to remove air and the tank doesn't require that it be piped off the top of the boiler.

Back to your problem: your gauge is old and may be inaccurate. The fill valve may also not be maintaing the proper pressure. The compression tank may also be completely filled with air which can also cause this issue. Leaks are also an issue and it looks like you have one from the packing of the compression tank isolation valve.

Can you post pics of the fill valve?

amin1992

Ironman said:

Yes to both questions.

Thanks. I have a tech from a larger company coming in about a week and a half. Maybe he can install some sort of automatic air purge valve on the lines. Glad to know I have series and not monoflo.

Thanks for your advice my friend

DZoro

Was the expansion tank drained when the tech was there?

JUGHNE

You do not want a permanent air purge vent on the lines.
After the zones are bled as much as possible, all the air must go into the compression tank at the ceiling.
As Ironman pointed out you want no air vents on the system.
Only air collection to put air into the tank.

amin1992

DZoro said:

Was the expansion tank drained when the tech was there?

I don't believe it was, there was no mention of that.

amin1992

JUGHNE said:

You do not want a permanent air purge vent on the lines.
After the zones are bled as much as possible, all the air must go into the compression tank at the ceiling.
As Ironman pointed out you want no air vents on the system.
Only air collection to put air into the tank.

I see, interesting - I thought there was supposed to be air vents so this is good to know.

Is the compression tank the same as the expansion tank? So air should go into that?

The system was purged twice and it had no effect on the gurgling.

Intplm.

@amin1992 read again what @ironman and @JUGHNE are telling you.
Your system will not work properly with a type of microbubble air separator or permanent air purge .The air with your design needs to be allowed to go to the top of the tank that you currently have installed.
So...yes. Air should go to the top of that tank.

Improvements to your system are quite doable.
Hopefully the tech you have coming will know to give you the best recommendations.

JUGHNE

You have a compression tank. The lower 2/3 of it is usually full of water that is compressing the air above it. If you lose that air cushion and the tank becomes water logged, then when the water heats up and expands there is no where for it to go other than open your pressure relief valve. There are air "scoops" which will collect the air from the water and have it bubble up to the compression tank. The next best thing is to have the tank connected to the boiler connection at the top such as yours.

An expansion tank does the same function except that there is a bladder between the air and water. Therefore any air coming out of the water has to leave the system thru an air vent.
The expanding water pushes against the bladder in the tank, compressing the air on the other side of the bladder.

One thing that has helped me with compression tanks is to have a hose connection above the valve that you have going to the tank. The horizontal pipe to the tank must slope up so air can find it's way into the bottom of the tank. If a tee is added for drain hose, the vertical pipe should be shortened
This way if the tank gets water logged you can isolate the tank and drain the water out of the tank. This avoids the hassle of having to purge the entire system.
But when you refill the tank you have to have the fill valve active to keep water pressure to fill the tank and retain the air cushion in it.
Do you have a pressure reducing valve (PRV)?

STEVEusaPA

Ironman said:

That primary control looks scary.

That looks like for draft assist, not a stack relay. Probably due to the flue pipe not installed by code. There's a cad cell wire coming from the aquastat into the burner.

Ironman

> @STEVEusaPA said:
> (Quote)
> That looks like for draft assist, not a stack relay. Probably due to the flue pipe not installed by code. There's a cad cell wire coming from the aquastat into the burner.

The aquastat is what I was referring to when I said primary control. And I agree: I never like to see a draft assist on anything - especially an oil burner.

HomerJSmith

I would drop that anachronistic tank and put in an Amtrol filtrol bladder tank and a honeywell super vent air eliminator.

I also saw, on a job, baseboard that didn't have a baseboard tee and coin vent that needed to have the air bled out of it. What the owner did was use a ice maker tap that supplies cold water to the refrigerator. He just strapped it on the baseboard tube and punctured the tube and opened and closed the tee handle when needed. It worked.

Replacing or adding a baseboard tee can be a real pain in the you know what.